下肢外骨骼机器人设计及实验研究

为实现下肢残障者的运动康复,设计液压驱动的下肢外骨骼机器人机构。针对下肢外骨骼的运动跟随需求,提出一种滑模控制器,并进行了控制仿真模拟。仿真结果表明：外骨骼采用该控制算法能较好地实现位置跟踪。基于dSPACE硬件在环实时仿真系统搭建了下肢外骨骼系统,进行了空摆实验、被动跟随实验及主动跟随实验。实验结果表明：设计的下肢助力外骨骼机器人能够为穿戴者提供助力,外骨骼样机的整体稳定性较好,对穿戴者具有良好的跟踪性能与快速响应性。     

基于滑模PID控制的下肢康复外骨骼控制研究

为增强外骨骼机器人在医疗方面的康复效果,通过研究人体运动机理及人体各关节运动数据,设计了一款基于液压控制的下肢外骨骼机器人。首先,通过建立外骨骼动力学模型,基于拉格朗日法求出髋关节、膝关节处的驱动力矩,建立了髋关节、膝关节的动力学方程;针对动力学模型在实际计算过程中存在着误差及摩檫等因素影响,提出了一种PID和滑模控制相结合的控制算法;运用Matlab软件进行了模拟仿真实验,仿真结果表明,该控制系统能够使外骨骼机械腿达到良好的跟随效果;最后搭建样机实验平台,验证了控制算法的有效性,能够满足患者进行主动康复训练的需求。     

基于卡尔曼算法的外骨骼运动预判与控制

在人机交互时,由于人体下肢外骨骼获取的传感器信号滞后于人体运动实际形式,从而导致外骨骼机器人无法实时跟随髋关节、膝关节的运动,出现不能提供助力的问题。设计了一种下肢外骨骼模型,在此基础上,通过力/力矩传感器来获取信号,利用基于卡尔曼滤波算法对获取到的信息进行运动预判,然后将预判信号输入到下肢外骨骼机器人模型简化后的二连杆运动学模型上,通过采用PD控制检验系统稳定性以及预判精确性。最后进行MATLAB仿真实验,结果表明:信号经过卡尔曼滤波后能够有效预判人体运动形式,外骨骼下肢摆动腿在人体运动时能够进行有效地跟随,从而弥补延时。     

一种新型助力携行下肢外骨骼设计及仿真

设计了一种非拟人型下肢外骨骼,主要是由座椅、髋关节、大腿部结构、膝关节、小腿部结构、踝关节和鞋子依次串联而成,采用电机驱动。对下肢外骨骼进行了自由度分配与结构分析,根据坐标变换,运用D-H法建立下肢外骨骼的运动学模型。建立了下肢外骨骼虚拟样机模型,利用多体动力学仿真软件ADAMS进行运动学仿真。仿真结果验证了理论模型的合理性,为后期进一步研究外骨骼提供了依据。     

液压驱动型负重外骨骼机器人液压系统设计

从人体运动特征出发,分析了液压驱动负重外骨骼机器人的整体骨架结构。根据负重外骨骼机器人的特点要求设计了一套完整的液压传动系统,对液压系统中液压泵、伺服阀和液压缸等主要元件进行了选型计算。利用Simhydraulics软件建立了负重外骨骼机器人液压系统仿真原理图,并对液压系统进行了仿真分析研究,由仿真结果证明了所设计液压系统的合理性。最后对液压驱动型负重外骨骼机器人技术面临的挑战进行了分析,为该液压系统的深化设计提供了参考。     

外骨骼机器人设计及其机械结构的有限元分析

为了提高士兵的承载能力,降低在运动过程中的能量损耗,设计了一种液压驱动的可穿戴外骨骼机器人,该外骨骼机器人下肢具有12个自由度。根据外骨骼机器人的功能和工作原理,分析了外骨骼机器人的关键部位,并设计了外骨骼机器人的各部分的尺寸。利用有限元软件ANSYS对外骨骼机器人进行建模,对下外骨骼机器人进行有限元静力学仿真,并对大腿部位进行瞬态动力学仿真。通过仿真研究分析,验证了机构设计的合理性,对外骨骼机器人的进一步研究提供了参考。     

外骨骼机器人处于摆动相后期系统模型仿真

结合人体解剖学对外骨骼机械人下肢运动进行分析,主要阐述外骨骼处在摆动相后期的运动,根据功率键合图和传递函数混合进行建模,利用SIMULINK对液压缸的压力、速度、加速度和阀芯位移进行仿真,通过仿真结果来验证系统运动的合理性。     

一种骑乘式下肢助行器结构设计与仿真分析

为了帮助老年人或腿脚无力人员行走,设计了一种骑乘式下肢助行器。首先将设计的机构在三维软件SolidWorks中制作成实体零件,并组装成装配体得到虚拟样机,然后对助行器在平地上进行助力行走的步态分析,求出助行器平稳助力行走时的各关节角变化规律,最后使用虚拟样机技术在ADAMS环境中将关节角变化规律用于样机的运动仿真分析。仿真结果表明,助行器虚拟样机能够稳定、适时的助力行走,验证了设计的功能和有效性。同时,也为下一步的选型优化和驱动控制研究奠定了基础。     

下肢外骨骼电液伺服控制系统的设计与仿真

根据已设计出的下肢外骨骼模型以及由公式推出的外骨骼运动特性,设计液压缸的负载轨迹情况;对液压控制系统进行静态特性和动态特性分析,确定出液压系统的参数;通过用Simulink仿真对P控制、PI控制、PID控制3种方法进行比较,最终确定利用PID控制方法驱动下肢外骨骼运动。     

圆形管道机器人的机构设计与运动分析

研制了一种适应圆形管道的管道探测机器人，机器人搭载实时视频传输系统，具有主动变径机构和可以独立控制的驱动模块。机器人通过主动变径机构的调整使驱动模块上的履带适应圆形管道内壁尺寸。为了分析机器人在圆形管道内部的运动位姿特性对机器人进行了运动分析，使用ADAMS软件对机器人进行运动仿真计算，研制了机器人实验样机，搭建了机器人管道內部运动适应性实验平台，在水平管道和坡度管道情况下对机器人运动特性开展了实验及分析。研究结果表明，该机器人在圆形管道中具有较好的运动适应性能。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.